fix(shared): drop .js extensions from relative imports for Metro

packages/shared/src/index.ts and all sub-modules used .js extensions on
relative imports (e.g. './admin/index.js') pointing at .ts source files.
TypeScript with moduleResolution: "Bundler" doesn't need them, and
Metro's eager exporter (used for preview / production builds) reads
them literally and fails — only the dev-server Metro fell back to .ts.

Workspace typecheck remains 8/8 green; Vite and TS Bundler resolution
already accept both styles, so desktop is unaffected.

packages/shared/src/supabase/client.ts

@@ -1,11 +1,11 @@
-import { createClient as createSupabaseClient, type SupabaseClient } from '@supabase/supabase-js';
+import { createClient as createSupabaseClient, type SupabaseClient } from '@supabase/supabase-js';
 
-import type { Database, SupabaseConfig } from './types.js';
+import type { Database, SupabaseConfig } from './types';
 
 // Typed client alias used throughout the app.
 export type AppSupabaseClient = SupabaseClient<Database>;
 
-// Inline serial lock — replaces Supabase's default `navigator.locks` based
+// Inline serial lock — replaces Supabase's default `navigator.locks` based
 // lock that occasionally throws "Lock was stolen by another request" when
 // the same origin opens multiple tabs / Tauri windows / HMR-reloaded
 // modules. We only have one client instance per process so a simple promise

packages/shared/src/supabase/index.ts

@@ -1,3 +1,3 @@
-export * from './bytea.js';
-export * from './client.js';
-export * from './types.js';
+export * from './bytea';
+export * from './client';
+export * from './types';